Electric incandescent lamp



Dec. 4, 1934. w J, GElGER ET AL 1,983,362

ELECTRI C INCANDESCENT LAMP Filed April 24, 1934 fNI/EN TUF. 5 I I J IL TER. JEEJGEA .41: FR ED 7? E'AEKILL A THEIR Ari "0R HEY Patented Dec. 4, 1934 UNITED STATES PATENT OFFICE I 1,983,362 ELECTRIC INCANDESCENT LAMP Application April 24, 1934, Serial No. 722,060

11 Claims.

Our invention relates to electric incandescent lamps and more particularly to lamps in which the filament should occupy a definite position in the bulb.

Miniature lamps, such as those used for flashlight service, are made by the buttseal method in which the exhaust tube is joined to the neck of the bulb and the leading-in wires are sealed in the glass of this joint. One of the disadvantages of this method of manufacturing lamps results from the sealing operation in which it is very diflicult to control the location of the filament in the bulb. In lamps used for flashlight service this disadvantage is of a serious nature since the filament will not occupy a definite position with reference to the usual reflector and lens of such devices. Moreover, the mounting structure of the filament is generally of a flexible nature and is therefore liable to derangement as the result of jarring or bumping.

According to our invention the above mentioned disadvantages are obviated by providing a mount and bulb structure in which the filament is definitely and fixedly located in the bulb by means of supports which are preferably portions of the leading-in wires themselves and which engage portions of the bulb.

Further features and advantages of our invention will appear from the following description of species thereof and from the drawing.

In the drawing Fig. 1 is an elevation partly in section showing how the bulb, mount and exhaust tube are preliminarily assembled; Fig. 2 is a similar view of an unbased lamp; Fig. 3 is an elevation, with the bulb in section, of a completed lamp comprising our invention; and Figs. 4, 6-9 are similar views of modified forms of mount and bulb structure, Fig. 5 being a plan, view of the lamp shown in Fig. 6.

Referring to Fig. 1, the mount structure comprises a pair of leading-in wires 10 which are suitably spaced apart at their inner ends by a bead 11 of insulating material such as glass sealed around portions thereof. The innermost ends 12 of said leading-in wires 10 are bent outwardly at an angle, the said ends being located a definite predetermined distance from the surface 13 of the bead 11. A filament 14 is mounted on the leading-in wires 10 at a predetermined distance from the surface 13 of the bead 11. The outer ends of the leading-in wires are shaped to comprise short laterally extending portions 15 and V-shaped portions 16. The mount is disposed in an inverted position as shown in Fig. 1 on the Deck of a cylindrical bulb 17 comprising a double convex lens 18 at its tip and an annular protuberant portion 19. The distance from the outwardly bent ends 12 to the lateral mid-portion 15 of the leading-in wires 10 is preferably such that the said ends 12 are suspended a short distance from the inner face of the lens portion 18 of the bulb, although the distance may be made such that the said ends 12 will engage the said inner face of the lens. An exhaust tube 20 is disposed above the bulb 1'7 in axial alignment 5 therewith. The exhaust tube 20 is lowered upon the neck of the bulb 17 and the said bulb and exhaust tube are then rotated about their longitudinal axes and a fiameis directed upon their edges, thus uniting the said edges as shown in 7 Fig. 2 and enclosing the lateral portions 15 of the leading-in wires. During the uniting of the edges of the bulb and exhaust tube, the joint is compressed, thus causing the mount to be lowered in the bulb until the outwardly bent inner 7 ends 12 of the leading-in wires engage the inner surface of the lens portion 18 of the bulb. Since the filament 14 was so mounted as to bear a definite relationship to the ends 12 of the leading-in wires (both being located definitely with respect to the surface 13 of the bead 11) the said filament is therefore located in a definite predetermined relationship to the lens 18. By means of this construction the leading-in wires and filament are fixedly supported with reference to the I lens 18 throughout the life of the lamp. During the rotation of the bulb and exhaust tube, the v-shaped outer ends 16 of the leading-in wires are preferably held, as by disposing them in vertical slots in blocks which are also rotated, so that the mount is maintained in a vertical plane during the sealing operation. The bulb is then evacuated through the exhaust tube after which the said tube is tipped-off as shown at 21 in Fig. 2. The lamp is then completed by attaching a base thereto which may be of the conventional screwthreaded type as shown inFig. 3 in which 22 is the shell and 23 is the end contact.

The annular protuberant portion 19 of the bulb 17 provides an abutting surface or shoulder for the edge of the shell 22 of the base and the said shell may therefore be conveniently and accurately located with reference to the lens 18 and filament 14. However, the said annular protuberant portion 19 may be dispensed with as shown in Fig. 4, in which the wall of the bulb is cylindrical throughout. The filament 14 in said Fig. 4 is also shown as peaked toward the lens 18. This form. of filament may be desirable to provide a more concentrated light source than no the linear filament shown in Fig. 3, particularly when a longer filament is desired It will be understood that this form of filament may be used in any of the modifications illustrated in the drawing." A coiled filament may, of course, also that portions 24 91 the leading-in wires 10 diverge toward the intersection of the *inner surface of the lens 18 and the wall of the bulb 1'7 and the end portions 25 thereof are arc-shaped and engage portions of the said intersection of the lens 18 and bulb 17. During the construction of the mount the said end portions 25 of the leading-in wires 10 and the filament 14 are located predetermined distances from the surface 13 of the bead 11 so that when the said mount is sealed in the bulb the said filament 14 will again bear a definite relationship to the lens 18.

The lamp shown in Fig. '7 comprises a pianoconvex lens 26 at the end of the bulb 17 having an indentation 27 at the center of the plane surface thereof. One of the leading-in wires 10 comprises an end portion 28 which extends to and engages the said indentation 27. Here again the tip of the end portion 28 of the leading-in wire 10 is located a definite distance from the surface of the bead 11 as well as the filament 14. The filament therefore is accurately positioned with respect to the lens 26. This mount structure may of course also be used with the double convex type of lens illustrated in Fig, 3 and the type of mount structure shown in Figs. 3 and 6 may be used with a plane-convex lens or any of the mount structures may be used with any type of lens.

The mount structures illustrated may also be used in a bulb which has no lens portions such as the bulb of an ordinary flashlight lamp, where accuracy of filament position is desirable. Fig. 8 illustrates a lamp in which the end wall 29 of the cylindrical bulb 17 is of uniform thickness, the mount structure being of the type shown in Figs. 3 and 4. The tips of the end portions 12 of the leading-in wires 10 engage the bulb at the intersection of the end wall 29 and the side wall thereof.

Fig. 9 illustrates a form of lamp having a spherical bulb 30 having a hollow tip 31, the inner surface of which is engaged by the tip of the end portion 32 of the leading-in wire 10 similar to the end portion 28 of the leading-in wire 10 of the mount shown in Fig. 7.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. An electric incandescent lamp comprising a bulb. a pair of leading-in wires sealed in said bulb, and a concentrated filament mounted on said leading-in wires, one of said leading-in wires extending to and engaging a portion of said bulb, the said extended portion of said leading-in wire being of a predetermined length and thereby locating said concentrated filament in a definite predetermined position in said bulb.

2. An electric incandescent lamp comprising a bulb, a pair of leading-in wires sealed in said bulb, a bead of insulating material sealed around portions of said leading-in wires and holding them in spaced relationship, and a concentrated filament mounted on said leading-in wires at a predetermined distance from a surface of said bead, one of said leading-in wires extending to and engaging a portionof said bulb, the end of said extended portion of said leading-in wire bebulb, a pair of leading-in wires sealed in said bulb,

ing also a predetermined distance from said surface of said bead and thereby locating said concentrated filament in a definite predetermined position in said bulb.

3. An electric incandescent lamp comprising a bulb having a lens portion at the end thereof, a' pair of leading-in wires sealed in said bulb, and a. concentrated filament mounted on said leadingin wires, one of said leading-in wires extending to and engaging a portion of said lens, the said extended portion of said leading-in wire being of a predetermined length and thereby locating said concentrated filament a definite predetermined distance from said lens.

4. An electric incandescent lamp comprising a and a concentrated filament mounted on said leading-in wires, each of said leading-in wires having an outwardly bent end portion extending to and engaging a portion of said bulb, the said extended portions of said leading-in wires being of a predetermined length and thereby locating said concentrated filament in a definite predetermined position in said bulb.

5. An electric incandescent lamp comprising a bulb having a lens portion at one end, a pair of leading-in wires sealed in said bulb, and a concentrated filament mounted on said leading-in wires, each of said leading-in wires having an outwardly bent end portion extending to and engaging a portion of said lens, the said extended portions of said leading-in wires being of a predetermined length and thereby locating said filament a definite predetermined distance from said lens.

6. An electric incandescent lamp comprising a bulb of substantially cylindrical cross-section having a lens portion at one end, a pair of leading-in wires sealed in said bulb, and a concentrated filament mounted on said leading-in wires, each of said leading-in wires having an outwardly bent end portion extending to and engaging a portion of said lens and the wall of said cylindrical bulb, the said extended portions of said leading-in wires being of a predeterminel length 120 and thereby locating said filament a definite predetermined d stance from said lens.

7. An electric incandescent lamp comprising a bulb having a double convex lens portion at one end, a pair of leading-in wires sealed in said bulb, and a concentrated filament mounted on said leading-in wires, at least one of said leading-in wires having. an outwardly bent end portion extending to and engaging a portion of the inner face of said lens, the said extended portion of said leading-in wire being of a predetermined length and thereby locating said filament a definite predetermined distance from said lens.

8. An electric incandescent lamp comprising a bulb having a wall portion of substantially cylindrical cross section, a pair of leading-in wires sealed in said bulb, and a concentrated filament mounted on said leading-in wires, at least one of said leading-in wires having an outwardly bent portion terminating in an arc-shaped portion engaging the junction of the wall portion and the end portion of said bulb, said arc-shaped end portion of said leading-in wire being located a predetermined distance from said filament and thereby locating said filament in a definite predetermined position in said bulb.

9. The method of making incandescent lamps which comprises making a mount by sealing a bead of insulating material around portions of a. pair of leading-in wires, trimming at least one 150 of said leading-in wins at a predetermined distance from a surface of said bead, mounting a filament at a predetermined distance from said surface of said bead, and sealing said mount in a bulb so that the said tip of said leading-in wire engages a predetermined portion of said bulb of said bead, mounting a filament at a predetermined distance from said surface of said bead, and sealing said mount in-a bulb so that the said outwardly bent portion of said leading-in wire engages a predetermined portion of said bulb thereby locating said filament in a predetermined position in said bulb.

11. The method of making incandescent lamps which comprises making a mount by sealing a bead of insulating material around portions of a pair of leading-in wires, providing an outwardly bent portion in at least one of said leading-in wires at a predetermined distance from a surface of said bead, mounting a filament at a predetermined distance from said surface of said bead, and sealing said mount in a bulb having a lens portion so that the said outwardly bent portion of said leading-in wire engages a portion of said lens thereby locating said filament a definite predetermined distance from said lens.

WALTER J. GEIGER. AIFRED T. GASKILL. 

